Domestic garbage disposal unit with impeller operable only above a predetermined speed range



Sept. 23, 1958 G. B. LONG 2,853,24

DOMESTIC GARBAGE DISPOSAL UNIT WITH IMPELLER OPERABLE ONLY ABOVE A PREDETERMINED SPEED RANGE Filed April 12, 1954 5 Sheets-Sheet 1 97 INVENTOR.

Sept. 23, 1958 G is LONG 2,853,248

DOMESTIC GARBAGE DISPO SAL UNIT WITH IMPELLER OPERABLEZ ONLY ABOVE A PREDETERMINED SPEED RANGE Filed April 12, 1954 5 Sheets-Sheet 2 52 INVENTOR. 3 George 8. Long.

: BY 40 4s I 4:3, His Attorney Sept. 23, 1958 G.- B. LONG 2,853,248

DOMESTIC GARBAGE DISPOSAL UNIT WITH IMPELLER OPERABLE ONLY ABOVE A PREDETERMINED SPEED RANGE 15 Sheets-Sheet 3 Filed April 12, 1954 Hg. 7 I

. mwzzvrox. 2| George B. Long v BY His Attorney relationship with the cutting surfaces.

United States Patent DOMESTIC GARBAGE DISPOSAL UNIT WITH 1N1- PELLER OPERABLE ONLY ABOVE A PREDE- TERMINED SPEED RANGE George B. Long, Dayton, Ohio, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application April 12, 1954, Serial No. 422,644

Claims. (Cl. 241--257) This application is a continuation-impart of my copending application S. N. 329,970 filed January 7, 1953, now abandoned.

This invention relates to a domestic appliance and more particularly to garbage disposal units.

One of the most serious ditficulties with garbage disposal units is the possibility of jamming the impeller.

It is an object of my invention to provide a simple inexpensive impeller for a garbage disposal unit which will not jam.

It is another object of my invention to provide a simple durable inexpensive impeller for a garbage disposal unit which will cut or grind the material only when the impeller operates above a predetermined speed range.-

It is another object of my invention to provide a simple durable inexpensive impeller for a garbage disposal unit which will rotate freely below a predetermined speed range without any interference and without any cutting or grinding action and without any wedging of splinters or chips between the impeller or shredder ring.

These and other objects are substantially attained in the form disclosed by having a vertically movable blade having fiat vertical sides pivoted above its center of gravity so that it disappears by downward movement into a slot when the impeller is rotated below a certain speed range. The location of the center of mass of the blade below the pivot pin causes it to be raised or projected upwardly into an exposed operating position when the impeller rotates above the predetermined speed range. The blade has its pivot point located close to or even beyond the center of the impeller so that the raised portion of the impeller will extend sufficiently close to the center of the impeller that large objects such as cabbage leaves and grapefruit hulls may be forced into cutting The impeller is economically made of a casting which carries the pivoted vane and an overlying sheet metal member, If the vane or impeller should jam, the vane can readily be pushed down manually through the top opening of the grinder to free the vane and impeller. Also the motor may be repeatedly reversed to free any jamming.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the invention is clearly shown.

In the drawings:

Figure l is a vertical sectional view embodying one form of my invention;

Figure 2 is a fragmentary vertical sectional view of the upper portion of the unit showing the drain control in the open position;

' Figure 3 is a vertical sectional view taken along the line 33 of Figure 6 through a different portion of the impeller showing recesses and drain apertures therein;

Figure 4 is a fragmentary sectional view taken along the line 4-4 of Figure 8 showing a modified form of impeller with a modified form of vane;

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Figure 5 is another fragmentary sectional View of a modified impeller taken along the line 5-5 of Figure 9 showing another modified form of vane;

Figure 6 is a top view of the impeller shown in Figures land 3;

Figure 7 is a sectional view taken substantially along the lines 77 of Figure 1;

Figure 8 is a sectional view taken substantially along the lines 8-8 of Figure 4;

Figure 9 is a sectional view taken substantially along the line 99 of Figure 5; and

Figure 10 is a fragmentary sectional view through a modified form of impeller similar to that shown in Figure 1 but provided with a return spring to aid the retraction of the impeller.

Referring now to the drawings and more particularly to Figure 1 there is provided a housing 20. The top of the housing 20 is provided with an external bead 220 which holds the rubber collar 22 held onto the bead 220 by its own elasticity. Surrounding the rubber collar 22 is a ring 222 provided with an inwardly extending flange 224 abutting against the lower outer surface of said collar 22. Resting upon the upper face of the collar 22 is a substantially flat ring 226. The drain opening in the sink 23 is provided with a connector 19 having an upper flange resting upon the edges of the drain opening. According to my invention, the lower portion of the connector 19 is provided with a groove holding a snap ring 228 of resilient metal. The inner rim of the flat ring 226 rests upon the snap ring 228. The ring 222 is provided with a plurality of conically pointed set screws 230 which cam downwardly the downwardly flanged rim of the fiat ring 226 to squeeze the collar 22 against both the upper and lower portions of the bead 220 to provide a resilient sound deadening support for the housing 20. Threaded bushings 232 are welded to the top of the ring 226 and have screws 233 threaded into them which are turned to force the flat ring 24 and the gasket 235 firmly into contact with the bottom of the sink 23.

The top of the housing 20 is provided with an annular groove 237 in which is held the outer beaded rim of the serrated web 21 of rubber. The rubber collar 22, the bottom of the connector 19 and a small metal ring hold in place the beaded rim of the web 21. The web 21 permits garbage to be pushed downwardly through the drain opening. The flanged connector 19 is provided with a bottom portion 25 having a valve opening which is adapted to be closed by the valve 26. The valve 26 is provided with a knob 18 so that the valve may be lifted and turned to the position shown in Figure 2 wherein the three projections 17 having notched lower ends with their notches resting upon the three webs in the bottom portion of the flanged connector 19. During grinding it is necessary to have water flowing through the disposer and sufiicient water should be supplied to keep a pool of water in the connector 19'so as to serve as a water seal to prevent any odors or even any particles or fluids from being projected out of the garbage disposer. This also will reduce the noise liberated in the kitchen.

Extending downwardly upon the inner wall surface within in the housing 20 are four recesses 27 providing four vertical projection 29. Beneath the housing 20 there is provided a shredder ring 31 preferably of suitable hardened stainless steel or cast stainless alloy. The shredder ring is provided with four sharp edged groups of projections 30 directly beneath the projections 29 of the housing 20. These groups of projections 30 are in the form of a series of wide trapezoidal projections arranged one upon the other in a manner similar to lap siding excepting they run in the reverse direction. These groups 30 are staggered vertically to prevent any grooving action. They have ground surfaces with sharp cutting edges which protrude inwardly from the inner wall surface of the shredder ring 31. The shredder ring 31 is also provided with a series of trapezoidal shaped projections 28 protruding inwardly around its lower portion immediately adjacent the upper rim of the impeller. The housing is provided with a flanged recessed portion 33 into which is fitted the shredder ring 31.

concentrically located within the interior of the shredder ring 31 is the impeller 34. This impeller 34 has its upper rim located about midway between the tops and bottoms of the trapezoidal projections 28. The periphery of the impeller 34 is smooth so that little cutting takes place by coaction with the projecions 28 of the shredder ring 31. The shredder ring 31 and the impeller 34 are slightly conical in shape with a taper of about 14 for each. This angle provides substantially the best cutting and cleaning action. The impeller includes a generally disk-shaped base 36 which is splined or keyed by the key 43 onto the upper end of the drive shaft 44 of an electric motor 38. This electric motor 38 is connected to a housing 40 fastened to the upper housing 20 in such a way as to hold in place the shredder ring 31. In addition to the splined or keyed connection between the drive shaft 44 and the impeller 34 there is provided a nut 46 threaded onto the upper end of the drive shaft 44 to hold the base 36.

The housing 40 is provided with a wall 48 extending over the top of the motor 38 and provided with a ball bearing 49 for the motor shaft 44. The ball bearing 49 is protected from the water and garbage material by a suitable shaft seal 50 and a dished flinger 47. The chamber beneath the seal 50 is provided with a drain 51 so as to dispose of any leakage which may pass through the seal 50 in the event that this shaft seal is not operating properly to completely prevent the passage of liquid into the chamber of the ball bearing 49. The flinger 47 collects any leakage during any idle period and whenever the shaft 44 rotates, it will fling the leakage into the drain 51. The housing 40 provides an impeller chamber 52 between the wall 48 and the shredder ring 31. At one side of this impeller chamber 52 is an outlet 54 provided with a swivel connection 55 adapted to be connected to a sewer.

Garbage disposal units jam most frequently by splinters or chips which are cut from the waste material as the impeller or motor are starting up or decelerating to a stop. These splinters and chips then get wedged between the impeller and shredder ring. These wedged splinters and chips cause the impeller to become stuck so that the motor is unable to start the rotation of the impeller. Sometimes they can be dislodged by repeated reversing of the motor but often it is necessary to call a plumber or repairman to disassemble the unit to remove the wedged splinters and chips.

According to my invention cutting only takes place at such times as the impeller 34 and motor 38 operate above a predetermined speed range such as 500 to 750 R. P. M. This enables the motor to start without load making possible the use of a lower cost low starting torque motor. It also enables the chips or splinters which are cut during the operation above the predetermined speed range to pass through the passages between the shredder ring 31 and the impeller 36 before the impeller stops rotating. This makes the unit self cleaning and prevents the unit from becoming jammed.

To accomplish this, the base plate 36 is covered by a sheet metal disk 56 fastened to the base by the screw 57. This disk 56 may be made of stainless steel sheet. The base 36 and the sheet 56 are provided with a radial slot 60 which is open at its outer edge and extends inwardly to a point at or adjacent the center of the base plate 36. The sides of this slot are preferably tapered at an angle of 7 diverging from top to bottom. Within this slot 60 there is provided a projecting and disappearing vane 62. The outer edge of this vane 62 is preferably formed on a radius about the pivot pin 66. The vane 62 is provided with an upwardly extending car 68 through which passes the pivot pin 66. When the impeller 34 is stationary the vane 62 falls by gravity until it is stopped by the inner end wall portion 67 of the vane slot 60. The disk 56 is contoured so that it forms a continuous circular bead in circumferential alignment with the car 68 and the remaining top surfaces of the vane 62 when the vane 62 is against the end wall 67 of the vane slot 60. Due to the upward extending location the ear 68 of the vane 62 and the upper location of the pivot pin 66 the mass of the vane 62 is considerably below the level of the pivot pin 66. Thus the top surface of the vane 62 is substantially flush with the top surface of the disk 56 so that as long as the vane 62 is retracted there will be no positive agency to forcibly carry any particles around the inner periphery of the shredder ring 31.

The pivot pin 66 is supported within a pair of cars 100 in the top of the base 36. These ears are covered by the covering disk 56 so that they do not interrupt the smooth top surface of the impeller 34. The base 36 is provided with four recesses 121 located about from each other. These recesses make it possible to push the pivot pin through the apertures in the ears 100. They also improve the flow of liquid and the flushing of particles through the grinding chamber. For this purpose the sheet metal disk 56 is provided with a plurality of perforations 123 over each of these recesses 121. This allows water to flow through the recesses to flush particles out of the impeller chamber 52. There may also be provided passages 101 connecting the recesses 121 with the sides of the vane slot 60 to flush the vane slot 60 if desired. The particles are also flushed from the trapezoidal projections 28 and the spaces in-between them and the impeller 34 by the flow of water in the spaces between the impeller 34 and the adjacent inner periphery of the shredder ring 31.

The blade 62 is so shaped that when the impeller 34 is below the predetermined speed range, the force of gravity will cause it to fall entirely within the slot 60 against the rear wall 67 of the slot 60. In this position the top surface of the blade is flush with the top surface of the disk 56 so that a substantially uninterrupted circumferentially uniform surface is presented. Since the center of mass of the blade 62 is well below the pivot pin 66, when the motor 38 rotates the impeller at speeds above the predetermined speed range the centrifugal force acting upon the blade 62 will cause it to move upwardly into the dot-dash line position shown in Figure 1. In this projected position the blade 62 will carry the waste material around. in contact with the shredder ring causing the waste material to be cut by the sharp edges of the projections 30 and 28.

This waste material will be forced downwardly by the angular position of the cutting edges of the projections 30 and 28 and by the 14 taper so that the waste material will move between the projections 28 into the impeller chamber 52. During the operation of the garbage disposal unit it is necessary that water flow from the sink through the open valve 26 into the housing 20 from which it flows through the space between the periphery of the impeller 34 and the shredder ring 31 as well as through the apertures 123 and the recess 121 into the impeller chamber 52. The flow of water carries the ground waste material out of the impeller chamber 52 and through the outlet 54 and the swivel connection 55 to the sewer.

The outermost corner 69 of the upwardly extending car 68 of the vane 62 has another unique function. Normally a half grapefruit hull cannot be ground if the rounded side is centrally located on the impeller. However in this construction the corner 69 of the ear 68 lifts up along with the rising of the vane or blade 62. Therefore this corner projects sufliciently far to engage the grapefruit hull to flip it over so that the hull will be properly ground by the edges of the projections 30 and 28. Other bulky garbage such as the butt ends of cabbage or lettuce are similarly engaged and moved into contact with the shredder ring by this corner 69.

The sides of the vane 62 are vertical and closely engage the upper edges of the slot 60. This prevents food particles from wedging in-between the sides of the blade and the sides of the slot. The downwardly diverging taper of the slot 60 prevents any ground particles from packing in the slot. The recesses 121 on either side of the ears 100 communicate through the passages 101 directly with the slot 60 beneath the sheet metal disk 56 so as to direct a water flushing action against the sides of the vane 62 so as to insure free movement of the vane 62 and to prevent any ground particles from collecting in the slot 60. This insures the freedom of' movement of the vane 62 under the combined forces of gravity and centrifugal action so that the vane is only projected upwardly and cutting only takes place above the predetermined speed range during which the material to be ground is carried around by the vane 62 in cutting engagement with the cutting projections 28 and 30 of the shredder ring 31. The material ground is readily forced downwardly between the impeller and shredder ring by the downward camming action of the cutting edges of the projections 28 and 30. Below the predetermined speed range the action of gravity causes the vane 62 to fall down to the position shown in full lines in Figure 1 so that the top surface of the impeller 34 becomes completely smooth and symmetric about the axis of the motor shaft 44. This prevents any cutting of any material during the deceleration of the motor and prevents chips and splinters from being formed and from jamming the impeller.

The motor 38 and the motor housing 40 are provided with a sheet metal enclosure 85 having an opening 87 for the outlets 51 and 54. According to my invention the bottom of the motor 38 is provided with a separate housing 89 which is rotatable relative to the housing 85. This housing 89 encloses the lower end of the motor 38 and the capacitor 91 which is fastened to the lower end of the motor 38 by the strap connection 93. The housing 89 is provided with a switch 95 which may be operated by an external operating lever 97. The lower cover 89 as well as the cover 85 are held in place by a screw 96 which threads into the bottom of the motor 38 in alignment with the axis thereof so that the housing 89 may be rotated upon the axis of the motor 38 to any suitable position relative to the housing 85. This makes it possible to locate the switch 97 at the most convenient point regardless of the position of the drain connection 55.

In Figure 10 there is shown a vane 362 which may be substituted for the vane 62 of Figure 1. This vane 362 is provided with a radial slot 371 beneath in which is located the tension spring 373 having one end connected by the pin 375 to the vane 362 and the other end connected by the pin 377 to the impeller 334 which is otherwise like the impeller 34. The spring 373 assists gravity in retracting the vane 362 and raises the speed range above which the vane rises and below which the vane falls.

In Figures 4 and the shredder ring 31, the motor housing 40 with the motor 38, the drive shaft 44, the bearing 49 and the shaft seal 50 are similar to the corresponding elements in Figures 1 to 3. In Figures 4 and 8 however the vane slot 160 extends inwardly across the center of the impeller 134 and a flat sided vane 162 is located within the vane slot 160 and pivoted upon a pivot pin 166 which extends transversely across the axis of the impeller 134 and the motor shaft 44. This pivot pin 166 is held within ears in the impeller casting 136. The impeller 134 is provided with a sheet member 156 providing a smooth top surface covering the irregularities of the casting 136. The impeller 134 may be provided with recesses similar to the recesses 121 and perforations similar to the perforations 123 in Figures 3 and 6. The lower surface of the vane 162 engages portions of the casting 136 to limit its downward movement. The long radius of the vane 162 makes the force of gravity more effective in retracting the vane and also makes necessary a higher rotational speed and higher centrifugal force before the vane 162 is projected out of its vane slot 160. It will also return to its lower position at a rela tively higher speed. The boss 169 of the vane lifts further up above the top surface of the impeller 134 so that it may more eifectively engage grapefruit hulls, butt ends of lettuce and cabbage and other similar garbage and flip them over and carry them into contact with the shredder ring 31 so that they may be properly ground.-

In Figures 5 and 9 there is shown another modified vane arrangement in which the vane 262 is located in the vane slot 260 of the impeller 234. The vane 162 extends entirely across the mid portion of the impeller 234 and is provided with a pivot pin 266 on the opposite side. The pivot pin 266 is held within projecting ears in the casting 236 of the impeller 234. The impeller 234 is provided with a top sheet member 256. In other respects, the impeller 234 may be provided with recesses communicating with the vane slot 260 in a manner similar to the other modifications. The long radius of the vane 262 increases the amount of centrifugal force required to lift it and increases the effect of gravity on the vane so that the vane will remain in its lower position over a greater speed range than the previous modifications and will lift or project at a higher speed. It will also return to its lower position at a relatively higher speed when the impeller slows down. This will provide an increased safety factor in preventing jamming of the impeller. In all modifications should any jamming occur which cannot be remedied by repeated reversing of the motor, it is possible to simply remove the valve 18 and by forcing the vane downward with a suitable tool such as a screwdriver to free the vane and the impeller so that normal operation can be resumed.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted as may come within the scope of the claims which follow.

What is claimed is as follows:

1. Comminuting apparatus including a housing enclosing a cutting chamber, an impeller within said cutting chamber having a periphery extending close to said housing, said impeller having an open ended slot in its periphery extending through the impeller from top to bottom inwardly from the periphery of the impeller, a flat sided vane within said slot extending out to the periphery of the impeller and having a hinge connection at its inner end above its center of mass to said impeller on the opposite side of the axis of rotation of said impeller from the open end of said slot, said vane having its upper surface substantially flush with the top of said impeller when in its lower position and having its center of mass below said hinge connection so as to be projected up above the surface of the impeller by sufiicient centrifugal force.

2. Comminuting apparatus including a housing enclosing a cutting chamber, an impeller within said cutting chamber having a periphery extending close to said housing, said impeller including a casting having an open ended slot in its periphery extending through the casting from top to bottom inwardly from said open end, a flat sided vane within said slot extending out to the periphery of said casting, a pivot pin extending transversely through the vane, said casting having protruding ears on opposite sides of the vane slot receiving and supporting said pivot pin, said impeller also including a sheet member overlying said casting having a surface concentric relative to the casting excepting for a slot registering with said slot in said casting, said sheet member having a concentric boss extending over and around said protruding ears, said vane when in its lower position having an upper surface substantially the same as a continuation of the surface of said sheet member.

3. Comminuting apparatus including a housing enclosing a cutting chamber, an impeller within said cutting chamber having a periphery extending close to said housing, said impeller having a vane slot in its upper surface, a hinged vane in said slot provided with unbalanced mass for projecting itself out of said slot in response to centrifugal force above a certain minimum and for retracting itself into said slot when the centrifugal force falls below said certain minimum, said impeller being provided with a recess between its upper and lower surfaces communicating with and opening into said vane slot and having a perforation through its upper surface communicating with said recess.

4. Comminuting apparatus including a housing enclosing a cutting chamber, an impeller within said cutting chamber having a periphery extending close to said housing, said impeller having an open ended slot in its periphery extending through the impeller from top to bottom inwardly from the periphery of the impeller, a flat sided vane within said slot extending out to the periphery of the impeller and pivoted at its inner end above its center of mass to said impeller and having substantially -vertical fiat sides, said vane having its upper surface substantially flush with the top of said impeller when in its lower position and having its center of mass below said pin so as to be projected up above the surface of the impeller by sufficient centrifugal force, and spring means extending between said impeller and said vane for providing a rotative force upon the vane in the direction assisting the action of gravity thereon.

5. Comminuting apparatus including a housing enclosing a cutting chamber, an impeller at the bottom of said cutting chamber having a periphery extending close to said housing, said impeller having a raised central portion and a vane slot extending inwardly into said raised central portion, a movable vane in said vane slot having a raised portion substantially concentric with said raised central portion, said vane and impeller having a transverse pivot pin located within said raised portions a substantial distance inwardly of the outer edge of said raised portions, the center of mass of said vane being substantially below said pivot pin so that when the impeller is rotated at a suficient speed centrifugal force will raise the portion of the vane outward from said pivot pin including its raised portion above the central raised portion of said impeller.

References Cited in the file of this patent UNITED STATES PATENTS 2,166,786 Alexoy July 18, 1939 2,220,729 Powers Nov. 5, 1940 2,225,171 Hommes Dec. 17, 1940 2,477,686 Coss Aug. 2, 1949 2,565,322 Powers Aug. 21, 1951 2,566,069 Powers Aug. 28, 1951 2,573,213 Miller Oct. 30, 1951 2,643,066 Lamb June 23, 1953 2,682,376 Frank June 29, 1954 2,730,308 Jordan Jan. 10, 1956 

